Okai Chisato was originally a member of the Hello! Project Kids in 2002.

In 2004 Berryz Koubou was formed, with the intention of rotating the kids throughout the unit. Okai didn’t make the original pick, and the idea was eventually dropped. The remaining kids ending up forming °C-ute in 2005. The group didn’t make its official debut until late in 2006, with their first official single released in February 2007.

She was a member of Little Gatas until she was added to Gatas Brilhantes H.P. in 2007.

She was a part of the Hello! Project unit called Athena & Robikerottsu consisting of Okai, Niigaki Risa, Mitsui Aika, and Nakajima Saki, in 2007. They will sing the opening and ending theme song for the anime Robby & Kerobby.

It was revealed on July 2009 that Okai Chisato would be in Tanpopo # with Kamei Eri, Mitsui Aika, and Kumai Yurina.

Trivia

Her younger sister, Okai Asuna, was a member of the Hello! Pro Egg.

Is good friends with Hagiwara Mai.

Has said Fujimoto Miki is the Hello! Project member she respects the most.